<html>
  <head>
    <script type="application/javascript">
      function draw() {
        var ctx = document.getElementById("canvas").getContext("2d");
        for (var i = 0; i < 6; i++) {
          for (var j = 0; j < 6; j++) {
            ctx.strokeStyle =
              "rgb(0," +
              Math.floor(255 - 42.5 * i) +
              "," +
              Math.floor(255 - 42.5 * j) +
              ")";
            ctx.beginPath();
            ctx.arc(12.5 + j * 25, 12.5 + i * 25, 10, 0, Math.PI * 2, true);
            ctx.stroke();
          }
        }
      }
    </script>
  </head>
  <body onload="draw();">
    <canvas id="canvas" width="300" height="300"></canvas>
  </body>
</html>
